Yves here. In the meantime, the WHO says not to worry about plastic in the form of microplastics, while admitting they don’t know much about the health impact. From European Scientist:

So far, there is no proof that microplastics in drinking water pose a risk to human health, according to a new safety review into the potential risks of plastic in drinking water released on 22 August by the World Health Organization (WHO).

The recent report was motivated by a worrying analysis published last year, which found some form of microplastic contamination in 93 per cent of bottled water purchased in 19 locations in nine different countries – a total of 259 bottles (1). In response, the WHO launched the recent safety review into the potential risks of plastic in drinking water.

That is not to say microplastics completely harmless. Instead, it seems we still have no idea whether — or even how — microplastics could be harmful

Rainwater samples collected across Colorado and analyzed under a microscope contained a rainbow of plastic fibers. Photograph: USGS (source)

I often worry whether we aren’t one of those species that self-eliminates, that commits “ecological suicide” as many bacteria do when they turn their environment too acid to live in. It’s certain we’re polluting the air with CO2 in a way that will change the climate from habitable to very inhospitable.

But we’re doing this in other ways as well — according to the latest news, surprisingly, with plastic. To be more exact, the microplastic that results from the breakdown of our trash, which as you likely know if you look at your garbage, is filled with plastic.

Microplastics are fibers that can be seen only with a microscope. The latest reports show that microplastic is not only present in abundance in the ocean, where much of our bulk plastic resides, but also in the air and, via the same settling effect that drops soot and dust to the surface of the earth, on the ground we walk across.

Day after day, year after year, minute after minute, a film of microplastic particles is raining on the earth. The more we produce it, the more we will live in it. If in a thousand years we revert as a species to Stone Age life, reduced in numbers and struggling to survive, we’ll find the ground, not rich in minerals as it was when our ancestors first walked on it, but rich in the indestructible garbage our descendants’ ancestors — us — cast off on the way to their own self-caused demise.

One report from April of this year in Science reveals the amount of plastic descending on the Pyrenees in France:

Prior studies have shown that microplastics, which can be ingested and inhaled by humans—and which may lead to reproductive issues in some marine mollusks—can rise up into the atmosphere and drop back to solid ground in the cities they come from. But scientists thought these plastics couldn’t travel very far from their urban sources.

To find out just how far they can go, the researchers collected particles falling from the sky in dust, rain, and snow for 5 months at the Bernadouze meteorological station in the Pyrenees mountains in southwestern France—100 kilometers from the nearest city.

To their horror, the authors found plastics, predominantly the kind from the single-use packaging used in shipping. From their sample, they determined that each day, an average of 365 plastic particles sifted down from above into the square meter surface of the collection device. If comparable quantities of airborne microplastic fall across the rest of the country, the researchers estimate roughly 2000 tons of plastic blanket France each year, they report today in Nature Geoscience.

Another report in the Guardian says this about plastic falling on the Rockies:

Plastic was the furthest thing from Gregory Wetherbee’s mind when he began analyzing rainwater samples collected from the Rocky Mountains. “I guess I expected to see mostly soil and mineral particles,” said the US Geological Survey researcher. Instead, he found multicolored microscopic plastic fibers.

The discovery, published in a recent study (pdf) titled “It is raining plastic”, raises new questions about the amount of plastic waste permeating the air, water, and soil virtually everywhere on Earth. …

Rainwater samples collected across Colorado and analyzed under a microscope contained a rainbow of plastic fibers, as well as beads and shards. The findings shocked Wetherbee, who had been collecting the samples in order to study nitrogen pollution.

There’s even plastic landing on the ice floes of the Arctic. According to the UPI in April: “New research published on Wednesday in Science Advances shows that even the remote ice floes of the Arctic have measurable amounts of microplastics and microfibers gracing their surfaces.”

We eat it, we drink it, we breathe it. Does it hurt us? Hard to imagine it doesn’t, though the subject is just now coming under scrutiny, as this study published in Science Direct notes:

Microplastics have recently been detected in atmospheric fallout in Greater Paris. Due to their small size, they can be inhaled and may induce lesions in the respiratory system dependent on individual susceptibility and particle properties. Even though airborne microplastics are a new topic, several observational studies have reported the inhalation of plastic fibers and particles, especially in exposed workers, often coursing with dyspnea caused by airway and interstitial inflammatory responses.

While the authors notes that inhaled microplastic can cause respiratory lesions, dispnea (shortness of breath) and inflammation, they don’t mention the relationship of chronic inflammation with cancer.

I’m frankly not sure we can address the problem of plastic, for the same reason we can’t address the problem of fossil fuel as a source of atmospheric CO2. Both are too embedded in the way our species lives.

Since plastics are not reactive but stable chemical structures the harm will come from its accumulation. I think I read a link here on potential harm in the digestive by facilitating the development of biofilms and altering the microbiome. Another instance would be the facilitation of pathogens setting in the respiratory tract increasing the frequency and severity of bronchitis, bronchiolitis and pneumonia. The incidence and pathogenicity of such diseases should be carefully monitored.

Plastics are stable, but often the additives are not. From what I know, there is very little research available on the behaviour of plastic additives (particularly those with endochrinal effects) in waste plastics when they are broken down to micro size. Most research seems to be on things like chemicals leaching from plastic containers under UV light, etc.

Additives is another concern. To my knowledge additives are used manly in food packaging as antioxidants, biocides etc and I don’t have any idea on their frequency in plastics and stability. Those additives consisting on small molecules will probably diffuse from the plastic to the environment.

> the behaviour of plastic additives (particularly those with endochrinal effects) in waste plastics when they are broken down to micro size.

That’s the deep issue. It’s been nearly two decades since I was in the lab of a US Fish and Wildlife study looking at reproductive/gender changes in wild fish. This is not new, just suppressed.

Another part is the micro size. Micro-particles may not be absorbed, for example passing through the intestinal tract. But nano-particles haven’t been tested for, and can zip right through cell walls. Assuming the airborne particles are derived from the same processes as rock dust, nanoplastics are as widespread and will remain in the airstream for a very long time.

Very fine particulates are the most dangerous component of air pollution. So this stands to reason. I wonder if it is possible to run a test to see how clogged and congested various birds, rats, bees, bats, etc become over time. In a lab where conditions are controlled. If plastics are inert, can’t they make us inert too? Nitrogen hasn’t embalmed us – how does it work? Gosh my body isn’t functioning. I wonder why?

Correct me if I’m wrong, but I seem to recall that the danger of asbestos was that the fibers are also inert. The response of the lungs is to wrap them forming lesions, which causes the problem. If microplastics behave similarly, then this is a serious problem.

Another issue with plastic waste, micro or not, is its ability to soak up evil chemicals like PCBs. When this happens with microplastics, the chemicals, now concentrated, can then be inhaled or ingested.

Its vital to know the precise source of airborne microplastics. There are two main sources in the environment – primary (i.e. purposely designed micro nodules used in cosmetics and cleaners, etc), and secondary (those arising from the breakdown of plastic waste). The main source in water seems to be from either primary sources or from fibres from cleaning petrochemical based clothing but airborne plastics may have different origins.

It seems WHO and others have forgotten about the precautionary principle. Until we can be absolutely certain this is safe there is no excuse not to ban microplastics for all but the most restricted uses. It certainly should not be used it ordinary consumer products. All sewage plants should be retrofitted to filter out microplastics from wastewater. The broader issue of secondary microplastics is much more difficult to deal with, especially in Asia where waste treatment/disposal is often primitive.

I don’t think you can ban microplastics, at least not without banning plastics.
The stuff in cosmetics and cleaners isn’t really microplastics in the sense of being invisible to the naked eye, and is too big to be inhaled.
Airborne microplastics may be from primary sources or from clothes washing, or may have different origins as you say. I’ve heard a lot may come from varnishes – polymer coatings applied to buildings, wind turbines and who knows what – which then flake off. That was in connection with microplastics in Arctic snow.

I thought a fair amount was going into the ocean, breaking down there, and then being carried up into the atmosphere as water evaporates. Seriously attacking the issue of plastic pollution in the oceans seems like it should be a priority.

Everyone has “forgotten” about the precautionary principle, primarily I suspect because the testing should occur over a much longer timescale that anyone in industry is willing to wait. For example, new drugs should really be tested over at least a generation. Yet the patents on them run out long before that. So pharma’s response is to include class action lawsuits as part of doing business, to the degree they can’t get them banned at all.

I can’t believe that we have been using plastics on such a large scale for so many decades and the lack of curiosity about any long term health effects on us. How many microplastics can accumulate in the lungs before they start having a serious effect on lung capacity? Will these microplastics pass through the digestive tract or will they also accumulate there as well. PK brought up the question of additives which is a whole new level of unknowns. I do not know how long it will take for these microplastics to deteriorate in the natural environment but I suspect that it will be longer than our recorded history up to date.

I remember back in the Disco Days it used to be “Raining Men. Hallelujah!.” And the Weather Girls would sing “I’m gonna go out to run and let myself get absolutely soaking wet.” Oh the good ole days.

So this one day, not but a few months ago, the bag checker at the grocer asked if I wanted paper or plastic? I replied, “Paper.” Then I proceeded to watch him put the produce in plastic and then put the plastic in a paper bag. I was too verklempt to say anything. So I left silently, and stoically, not even shaking my head.

You foul your nest, you die. It’s really simple and easy to comprehend. Our ecosystem is like a garden we grew up in and we require that garden to survive, even flourish, in order to survive ourselves. Can we all ‘get’ that? Absolutely not. We as a species are categorized as ‘over killers.’ Rats are in the same folder. I’m betting on the rats.

Small point, oil producers are determined to produce, thus turning oil into plastics has become a really big business. Help keeps the price of oil up. Bankers like it. Not going to stop. Trump EPA sees no harm.

One thing perhaps worth mentioning here is nanotechnology. If I understand correctly, that is like the plastics problem but at the nano level.

I have seen many articles about “the nanotech revolution” and the thought that always follows is: “…and what happens when all of that crap gets dumped into the environment?“ There is of course the infamous “grey goo” endgame scenario but as microplastic pollution indicates it’s not a matter of the stuff self replicating, rather it’s what happens when it begins to saturate the natural world.

Every summer I hike high up into the Colorado Rockies, even to the timberline, in search of my favorite prey; trout. Unspoiled by pollution, unsullied by whatever we dump in rivers that finds its way to the ocean, raised in splendid isolation between ridges of sighing pines, fed by mountain snow and summer shower, the essence of purity itself.

And now you’ve gone and ruined it! Never again will I be able think of trout in mountain lakes as exempt from human contamination!